I have a 1967 mercury 650. I have changed the impeller and still cant get water to come out of the tell tale. I have hooked up a hose directly to the water tube and still no output from the tell tale. Water pours out of the mid case. Is this normal? Does the entire thing have to fill up befor water comes out? What am I doing wrong?(the motor has been run with muffs and in a tub of water. No high rpm though.)
Make (of engine): Mercury
Model (of engine): 650
I also blew compressed air back through tell tale hose and it had no resistance. Could also hear air comming yhrough the mid shaft
Welcome,this question may need more than a single answer. Please post back with additional questions on this at any time.The water fills the block. There is no real restrictions.If you are not getting any water out the tell tale with a water hose on the water tube in the midsection then you either have a blockage under the powerhead or a corroded adapter plate.For an engine of your age taking the exhaust plate or rear water jacket off can be problematic. I would suggest you pull the powerhead off and examine the water tube and the adapter plate under the powerhead for corrosion or blockage. It is not uncommon on older engines to have the adapter plate corroded and broken and no water making it into the powerhead.Post back what you find.Thanks
So water should only be coming out of the tell tale and not back down the midsection? I have also seen in a few forums that water may not come out at lower rpms. I don't really believe that this is right but I'm no expert. I can hear air comming out of the mid section but cant feel it at the l/u side of the water tube. Does this reinforce your theory? Just want to make sure before I remove the powerhead! I don't want to mess with to much on the top half because it is running quite good.
Relist: Other.did not respond to my reply
Sorry I'm working with multiple customers here, busy for a Sunday night!At any rpm you should have water. The way the system works is it fills the exhaust side of the engine then fills the back water jacket from the bottom up. The block fills then is dumped into the exhaust under the powerhead and out the exhaust at the lower unit. So yes you should have water with the exhaust.The tell tale, early engines didn't have it although it was commonly added on to early engines should show water as soon as that part of the block has water.There is also an exhaust relief port on the back of the midsection, here you won't get much water at low speeds. Do you have the elbow and hose from between the #2 & 3 cylinders/Also you can start and run the engine and feel the exhaust side of the engine. You should be able to feel the cold water as it fills and it shouldn't get hot. If it does get hot you definitely are not getting water there.Try these and let me know what you get.
35 years experience, Certified Master Technician, All Major Outboards, Sterndrives, Hi-Performance